import { Injectable, Injector } from '@angular/core';
import { Router } from '@angular/router';
import {
    HttpInterceptor,
    HttpRequest,
    HttpHandler,
    HttpErrorResponse,
    HttpSentEvent,
    HttpHeaderResponse,
    HttpProgressEvent,
    HttpResponse,
    HttpUserEvent,
} from '@angular/common/http';
import { Observable, of, throwError } from 'rxjs';
import { mergeMap, catchError } from 'rxjs/operators';
import { NzMessageService } from 'imeepos-antd';
import { environment } from '../../../environments/environment';
import { HttpClient } from '@angular/common/http';
import { _HttpClient } from 'imeepos-delon';
/**
 * 默认HTTP拦截器，其注册细节见 `app.module.ts`
 */
@Injectable()
export class DefaultInterceptor implements HttpInterceptor {
    constructor(
        private injector: Injector
    ) { }

    get msg(): NzMessageService {
        return this.injector.get(NzMessageService);
    }

    private goTo(url: string) {
        console.log(url);
        setTimeout(() => this.injector.get(Router).navigateByUrl(url));
    }

    private handleData(
        event: HttpResponse<any> | HttpErrorResponse,
    ): Observable<any> {
        // 可能会因为 `throw` 导出无法执行 `_HttpClient` 的 `end()` 操作
        this.injector.get(_HttpClient).end();
        // 业务处理：一些通用操作
        switch (event.status) {
            case 200:
                // 业务层级错误处理，以下是假定restful有一套统一输出格式（指不管成功与否都有相应的数据格式）情况下进行处理
                // 例如响应内容：
                //  错误内容：{ status: 1, msg: '非法参数' }
                //  正确内容：{ status: 0, response: {  } }
                // 则以下代码片断可直接适用
                // if (event instanceof HttpResponse) {
                //     const body: any = event.body;
                //     if (body && body.status !== 0) {
                //         this.msg.error(body.msg);
                //         // 继续抛出错误中断后续所有 Pipe、subscribe 操作，因此：
                //         // this.http.get('/').subscribe() 并不会触发
                //         return throwError({});
                //     } else {
                //         // 重新修改 `body` 内容为 `response` 内容，对于绝大多数场景已经无须再关心业务状态码
                //         return of(new HttpResponse(Object.assign(event, { body: body.response })));
                //         // 或者依然保持完整的格式
                //         return of(event);
                //     }
                // }
                break;
            case 401: // 未登录状态码
                // this.goTo('/passport/login');
                break;
            case 403:
            case 404:
            case 500:
                // this.goTo(`/${event.status}`);
                break;
            default:
                if (event instanceof HttpErrorResponse) {
                    console.warn(
                        '未可知错误，大部分是由于后端不支持CORS或无效配置引起',
                        event,
                    );
                    this.msg.error(event.message);
                }
                break;
        }
        return of(event);
    }

    intercept(
        req: HttpRequest<any>,
        next: HttpHandler,
    ): Observable<
    | HttpSentEvent
    | HttpHeaderResponse
    | HttpProgressEvent
    | HttpResponse<any>
    | HttpUserEvent<any>
    > {
        // 统一加上服务端前缀
        let url = req.url;
        if (!url.startsWith('https://') && !url.startsWith('http://')) {
            url = environment.SERVER_URL + url;
            console.log(url);
        }
        const newReq = req.clone({
            url: url,
        });
        return next.handle(newReq).pipe(
            mergeMap((event: any) => {
                // 允许统一对请求错误处理，这是因为一个请求若是业务上错误的情况下其HTTP请求的状态是200的情况下需要
                if (event instanceof HttpResponse && event.status === 200)
                    return this.handleData(event);
                // 若一切都正常，则后续操作
                return of(event);
            }),
            catchError((err: HttpErrorResponse) => this.handleData(err)),
        );
    }
}
